Image detectors, such as focal plane arrays, CMOS detectors, CCD detectors, and the like, typically utilize relatively broadband detector elements that are not able to distinguish the particular wavelength of energy received by the detector element. In some applications, color filters, such as a Bayer filter, may be utilized at the image plane to selectively allow light of various frequencies to pass onto particular detector elements, and the sensor data generated by the detector elements may be processed, such as by interpolation, to infer which wavelengths were received by which detector elements. However, in many applications, filters at the image plane suffer shortcomings, such as the introduction of crosstalk.
Many applications require the ability to identify certain wavelengths of energy in a scene. For example, the presence of energy in certain wavelengths may be indicative of an event, such as a missile launch or a nuclear material leak. In the context of energy in the infrared (IR) wavelength band, two individual mid-wave IR focal plane arrays (FPA) may be useful, for example, to facilitate clutter rejection in certain applications. Unfortunately, the cost and complexity of stacked FPAs is prohibitive for many applications. Moreover, the use of a color filter array may cause excessive spectral crosstalk.